[Offline Pages] Add cached offline page utils and show usage in settings.

chrome/browser/browsing_data/cache_counter.h

Index: chrome/browser/browsing_data/cache_counter.h
diff --git a/chrome/browser/browsing_data/cache_counter.h b/chrome/browser/browsing_data/cache_counter.h
index 3b4d4d28ce945e51c28602e1a8fbfd563ca7c948..6505631318c2dbd79c979c5064be8ffcf7282503 100644
--- a/chrome/browser/browsing_data/cache_counter.h
+++ b/chrome/browser/browsing_data/cache_counter.h
@@ -42,15 +42,16 @@ class CacheCounter : public browsing_data::BrowsingDataCounter {
 
  private:
   void Count() override;
-  void OnCacheSizeCalculated(int64_t bytes, bool is_upper_limit);
+  void OnCacheSizeCalculated(bool is_upper_limit, int64_t cache_bytes);
   void FetchEstimate(
       base::WeakPtr<browsing_data::ConditionalCacheCountingHelper>);
 
   Profile* profile_;
-  bool pending_;
+  int64_t calculated_size_;
+  bool is_upper_limit_;
+  int pending_sources_;
 
   base::WeakPtrFactory<CacheCounter> weak_ptr_factory_;
-
 };
 
 #endif  // CHROME_BROWSER_BROWSING_DATA_CACHE_COUNTER_H_